Well the glass rod has a positive charge. So when it is near the metal it attracts the sea of electrons(metallic bonding in a metal can be viewed as nuclei in a sea of electrons.(a crude visualization)).

As the electrons flood to the side nearest to the charged glass rod, a slight -ve charge develops at this end of the metal rod, whereas a slight positive charge develops at the other end. This is induction.

The electrons dont flow continuosly as a -ve charge build up(of strength equal to that of the charge on the glass rod.) and this repels the flow of more electrons.